I was watching the news on that. But it is interesting that it matches up with her using a 1924 seimans hear aid device, which was held like a mobile phone and about the same size.
Because like people have been asking, if it is a cell phone who is she talking to? Also if it was being used everyone would be rather curious.
I for one hope that by the time time travel is invented, that phones are a little smaller and hands free then that!